Substrate Transfer End-Effector Collision Detection by Torque Difference
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Solution Overview
Problem
Substrate transfer apparatuses in semiconductor facilities face challenges in detecting collisions of the end-effector, leading to potential damage to the apparatus, collision targets, or substrates due to incorrect positioning or errors in transfer programs.
Innovation Solution
The substrate transfer apparatus incorporates a collision detection unit that measures torque values of the motor, calculates torque difference values between measurements taken with a time difference, and determines collisions based on these values. This unit includes a control system that stops or reverses the motor's driving when a collision is detected.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the substrate transfer apparatus operates without collision detection, then the device complexity is reduced, but the reliability deteriorates due to potential damage from collisions
Solution Approach 1:
The patent replaces complex mechanical collision detection mechanisms with an electrical measurement system. The torque measurement part electronically monitors the torque value of the motor during substrate transfer operations, substituting physical sensors or mechanical switches with electrical signal processing to detect collision conditions.
Solution Approach 2:
The patent introduces torque value as an intermediary parameter to detect collisions. Instead of directly detecting physical contact between the end-effector and obstacles, the system measures the torque value of the motor, which serves as an indirect indicator of collision conditions through the transmission mechanism.
2Measurement precision
If segmented collision determination references are used for different movement speeds and distances, then the measurement precision is improved, but the device complexity increases
Solution Approach 1:
The patent creates a universal collision determination reference that functions across all movement speeds and distances. The single reference value can be applied universally to determine whether a measured torque value indicates collision, eliminating the need for multiple segmented references while maintaining detection accuracy through the fundamental relationship between torque and collision force.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution effectively detects collisions of the end-effector by analyzing torque changes over time, allowing for timely intervention to minimize damage. The method is applicable across various movement speeds and distances, eliminating the need for segmented collision determination references.
Implementation Method 1
a torque measurement part configured to measure a torque value of the motor
Data Source
Figure 1(a)~1(b)
Figure 2
Figure 3(a)~3(b)
AI summary
The present invention relates to a substrate transfer apparatus detecting a collision of an end-effector, and an operation method thereof. The substrate transfer apparatus comprises: an end-effector for supporting a substrate; a motor for providing power for moving the end-effector; a collision detection unit for detecting a collision of the end-effector; and a control unit for controlling the driving of the motor according to the collision detection of the collision detection unit. The collision detection unit may comprise: a torque measurement unit for measuring a torque value of the motor; a difference value calculation unit for calculating a torque difference value between two torque measurement values measured with a time lag therebetween; and a collision determination unit for determining a collision of the end-effector on the basis of the torque difference value.